1. Field of the Invention
This invention relates to a system for cleaning and clearing windows and external rear view mirrors of a vehicle and particularly to a system which provides conditioned ventilation to the exterior mirrors and windows of a motor vehicle. The invention may be used for a variety of moving transportation means such as cars, trucks, all-terrain vehicles, trains, ships, etc.
2. Description of the Prior Art
The accumulation of dirt and/or precipitation on the exterior of side windows of a motor vehicle is a common problem for operators of motor vehicles. This accumulation prevents and obstructs the operator's visibility to the periphery and more importantly, the ability to see in the exterior rear view mirror any traffic approaching in the adjoining lane. Moisture will collect on the viewing surface of exterior rearview mirrors during times of precipitation. This condition has the ability to distort the reflective properties of images viewed therein. This situation is further compounded during periods of darkness when the reflection of headlights upon the moisture covered rearview mirror creates additional visual distortion to images viewed therein.
Various improvements have been made to exterior rearview mirrors including but not limited to: remote movement mechanisms (e.g. mechanical means to move mirrors from inside an automobile with the windows up), reduced glare viewing surfaces and structural housings designed to improve the aerodynamics of air flow around the circumference of the mirror, and mechanical wiper assemblies.
A number of solutions have been proposed in the prior art to solve the problem of clearing the rear view mirrors from dirt and water condensate. They can be generally combined into two groups: passive air deflectors and active air blowers. The first group consists of a variety of simple and inexpensive "add-on" devices aimed at collecting the incoming air during the movement of a vehicle and projecting it onto the surface of the rear view mirror. For example, a U.S. Pat. No. 3,598,469 was granted to Mr. William J. Landen on Aug. 10, 1971. Through the use of air pressure gradients resulting from the forward motion of a motor vehicle, moisture would be removed from the viewing surface of an exterior rearview mirror. Other examples of such passive air deflectors may be found in the following U.S. Pat. Nos. 5,868,867; 5,815,315; 5,760,956; 5,343,328; 5,179,470; 4,979,809; 4,963,011; 4,903,581; 4,898,458; and 4,869,581. These devices have the advantage of being reasonably universal so as to be usable for a number of vehicles. They also work in a satisfactory way during a high speed movement of a vehicle. However, at low speeds (which is most likely in bad weather conditions!) or when the vehicle is not moving at all, these devices lose their ability to provide air flow. Also, they are inherently incapable of conditioning the air flow such as to increase its temperature or reduce humidity, all of which may be helpful in extreme weather conditions.
The use of various active air blowers provide improved effectiveness of these systems by removing their dependency of the speed of the vehicle and by allowing some air conditioning to occur. Another advantage of these systems is that they allow the clearing of the side windows as well as the rear mirrors. At the same time, these systems are complex and hence vehicle-specific. They assume incorporation of unique design elements with the on-board air-system of a vehicle and can not be easily adapted to be used for a variety of different vehicles. In addition, in many cases the air blowers are underpowered and blow the air at an acute angle towards the surface of the mirror so that the incoming moist and cold air flow simply overwhelms their function.
Examples of such devices can be found in the following U.S. Pat. Nos. 6,012,817; 5,953,158; 5,903,389; 5,383,054; 4,981,072; 4,561,732; 4,462,303; 4,439,013; 4,350,084; 3,877,780; 3,859,899; as well as in a PCT application No. WO 88/00142 and a UK application No. 2,262,441A.
Another limitation of the prior art devices is in the way the air flow is often organized. Typically, a narrow long passage opening is present in the devices of the prior art and the air is emitted therethrough does not provide for optimal coverage of the surface of the mirror or a side window.
Therefore, the need exists for a universal system for maximal clearing of the rear view external mirrors and the side windows of a vehicle which is free from the above mentioned drawbacks.